Background Maternal morbidity is common in Bangladesh, where the maternal mortality rate has plateaued over the last 6 years. Maternal undernutrition and micronutrient deficiencies contribute to morbidity, but few interventions have measured maternal outcomes. We compared reported prevalence of antepartum, intrapartum, and postpartum complications among recently delivered women between maternal nutrition intervention and control areas in Bangladesh. Methods and findings We conducted a cross-sectional assessment nested within a population-based cluster-randomized trial comparing a nutrition counseling and micronutrient supplement intervention integrated within a structured home-based maternal, newborn, and child health (MNCH) program to the MNCH program alone in 10 sub-districts each across 4 Bangladesh districts. Eligible consenting women, delivering within 42–60 days of enrollment and identified by community-level health workers, completed an interviewer-administered questionnaire detailing the index pregnancy and delivery and allowed review of their home-based care register. We compared pooled and specific reported antepartum, intrapartum, and postpartum complications between study groups using hierarchical logistic regression. There were 594 women in the intervention group and 506 in the control group; overall, mean age was 24 years, 31% were primiparas, and 39% reported facility-based delivery, with no significant difference by study group. There were no significant differences between the intervention and control groups in household-level characteristics, including reported mean monthly income (intervention, 6,552 taka, versus control, 6,017 taka; p = 0.48), having electricity (69.6% versus 71.4%, p = 0.84), and television ownership (41.1% versus 38.7%, p = 0.81). Women in the intervention group had higher recorded iron and folic acid and calcium supplement consumption and mean dietary diversity scores, but reported anemia rates were similar between the 2 groups (5.7%, intervention; 6.5%, control; p = 0.83). Reported antepartum (69.4%, intervention; 79.2%, control; p = 0.12) and intrapartum (41.4%, intervention; 48.5%, control; p = 0.18) complication rates were high and not significantly different between groups. Reported postpartum complications were significantly lower among women in the intervention group than the control group (33.5% versus 48.2%, p = 0.02), and this difference persisted in adjusted analysis (adjusted odds ratio [AOR] = 0.51, 95% CI 0.32–0.82; p < 0.001). For specific conditions, odds of retained placenta (AOR = 0.35, 95% CI 0.19–0.67; p = 0.001), postpartum bleeding (AOR = 0.37, 95% CI 0.15–0.92; p = 0.033), and postpartum fever/infection (AOR = 0.27, 95% CI 0.11–0.65; p = 0.001) were significantly lower in the intervention group in adjusted analysis. There were no significant differences in reported hospitalization for antepartum (49.8% versus 45.1%, p = 0.37), intrapartum (69.9% versus 59.8%, p = 0.18), or postpartum (36.1% versus 29.9%, p = 0.49) complications between the intervention and control groups. The main limitations of this study are outcome measures based on participant report, non-probabilistic selection of community-level workers’ catchment areas for sampling, some missing data for variables derived from secondary sources (e.g., dietary diversity score), and possible recall bias for reported dietary intake and supplement use. Conclusions Reported overall postpartum and specific intrapartum and postpartum complications were significantly lower for women in intervention areas than control areas, despite similar rates of facility-based delivery and hospitalization for reported complications, in this exploratory analysis. Maternal nutrition interventions providing intensive counseling and micronutrient supplements may reduce some pregnancy complications or impact women’s ability to accurately recognize complications, but more rigorous evaluation is needed for these outcomes., Catherine Todd and colleagues reveal that nutritional education and micronutrient supplements can reduce intrapartum and postpartum complications in pregnant women in Bangladesh., Author summary Why was this study done? Adequate nutrition during pregnancy reduces risks of poor infant outcomes, like low birthweight, but there is relatively little information about whether nutrition is linked to reducing a woman’s risk of pregnancy complications. Maternal nutrition interventions starting during pregnancy are being implemented at scale in multiple settings, including in Bangladesh, and determining whether these interventions reduce maternal complications may strengthen efforts to implement similar interventions to optimize maternal and newborn health. What did the researchers do and find? At the time of the endline evaluation for the parent trial—which compared an intervention of home-based intensive maternal nutrition counseling and iron and calcium supplement provision combined with home-based antenatal care to home-based antenatal care alone—we interviewed women who had delivered within the last 60 days to inquire about complications during pregnancy, during delivery, and after delivery. This study included 594 women in the intervention group and 506 in the control group across 4 districts in Bangladesh; women in the 2 groups were similar with regard to number of prior pregnancies, age, and household assets. Reported complication rates during pregnancy or during delivery were somewhat lower among women from intervention areas, while reported complications after delivery were significantly lower among women from intervention areas, compared to those from control areas. What do these findings mean? Differences in reported complication rates may be due to actual differing levels resulting from intervention exposure, or to different perceptions of what conditions constitute pregnancy complications, which could also result from intervention exposure. The intervention did not appear to impact care-seeking during pregnancy or during labor based on similar skilled/facility-based care statistics for the intervention and control groups. Community-based care providers recorded key obstetric events accurately and at high rates, but greater understanding of client and provider perceptions regarding what constitutes maternal complications and ensuring provision of appropriate care are needed. Given the cross-sectional nature of the study and that complications were self-reported, the findings should be interpreted with caution.